1. Field of the Invention
The invention relates to a wire twist-preventing device for preventing twisting when wires are wound around a winding frame using a vertical coil winding machine, particularly to a wire twist-preventing device in a winding machine for preventing the twist of the wires which are produced when continuously winding, formed of a plurality of lines or wires which are arranged in parallel with one another in a tape shape.
2. Description of the Related Art
In the coil winding machine of this type, when a winding frame, which has a plurality of winding stages winding diameters of which gradually increase upward, is lowered stage by stage, wires supplied through rotating flyers are sequentially wound around each stage of the winding frame to form a coil which is inserted into a coil insertion jig disposed under the winding frame.
FIG. 11 is a perspective view for briefly explaining a main portion of a conventional winding machine together with a coil insertion jig.
A winding frame 1 comprises a left winding frame 1a and a right winding frame 1b. The left winding frame 1a has a plurality of winding stages 1aa, 1ab, 1ac and 1ad which gradually increase upward in winding diameter, while the right winding frame 1b has a plurality of winding stages 1ba, 1bb, 1bc and 1bd which also gradually increase upward in winding diameter, and the left winding frame 1a and the right winding frame 1b are mounted on a supporting plate 2 which is movable up and down.
Four spindles 3 are provided outside each winding stage of the left and right winding frames 1a and 1b so as to be movable up and down. Pressing plates 4 are radially fixed to the lower ends of each spindle 3 so as to insert up and down into gaps defined but not shown in the left and right winding frames 1a and 1b, wherein when each spindle 3 moves downward, the coil i.e. the wire wound around the winding frame 1 is discharged downward.
A flyer 6 thorough which a wire 5 for forming a coil is inserted is rotatably provided outside these components. When the flyer 6 is rotated about the outer periphery of the winding frame 1, the wire 5 is wound around the winding frame 1 to form a coil.
The coil thus displaced downward by the pressing plates 4 is received by a coil insertion jig 7 having a plurality of blades 7a which are disposed circumferentially thereon, and then it is inserted into the stator core of a motor, not shown.
In the practical winding, the flyer 6 is rotated in a state where the a winding frame 1 is lowered from the state shown in FIG. 11 so that the winding stage 1aa positioned at the lowermost end of the left winding frame 1a slightly bites into the tip end of the coil insertion jig 7. As a result, the wire 5 is wound around the winding stages 1aa and 1ab to form the coil. At the same time, the pressing plates 4 integrated with the spindles 3 are moved up and down so as to move the formed coil sequentially downward, thereby displacing the formed coil from the winding stages 1aa and 1ab. The displaced coil is inserted into gaps of the blades 7a of the coil insertion jig 7 so that most of the formed coil is inserted into the coil insertion jig 7 except a part thereof which remains on the first winding stages 1aa and 1ab at the final stage of the first stage winding.
If a given wire is wound around the first winding stages 1aa and 1ba, the winding frame 1 is lowered by one stage, then the second winding stages 1ab and 1bb are positioned in a winding position so that the wire forming the terminal end portion of the first stage coil formed on the winding stages 1aa and 1ba is guided onto the second stages 1ab and 1bb to form the second stage coil. Most of the second stage coil is inserted into the coil insertion jig 7 except a part thereof which remains on the second winding stages 1ab and 1bb.
Likewise, the wire is wound around third and fourth winding stages 1ac, 1bc, and 1ad, 1bd, and is mostly inserted into the coil insertion jig 7. When a given stage of winding is completed, the spindles 3 are lowered to the lowermost portion and the part of the coil remaining on each winding stage is pressed by the pressing plates 4 and is completely inserted into the coil insertion jig 7, so that the coil winding for the first pole is completed.
Subsequently, the wire forming the terminal end of the coil of the first pole is gripped by a gripper, not shown, and the coil insertion jig 7 is rotated by a given rotary angle in response to the number of poles of the stator core so as to perform a coil winding for the next pole. The wire 5 is cut off to complete the winding for one stator core upon completion of coil winding for given poles.
As mentioned above, a plurality (even number) of wires are continuously wound when a coil winding for the stator core is usually performed, but the case of four poles of the stator core will be considered for simplifying the explanation. At this time, the rotating direction of the flyer 6 changes in the order of normal rotation.fwdarw.reverse rotation.fwdarw.normal rotation.fwdarw.reverse rotation as shown in FIG. 12 supposing that the clockwise direction CW is referred to as normal rotation and the counterclockwise direction CCW is referred to as reverse rotation.
However, when a plurality of wires, which are arranged in parallel with one another in a tape shape, are wound, the wires are wound around the winding frame in a twisted state during the winding. If the twist is produced in the wires, the thickness of each wire wound around the winding frame in the radial direction of the wire increases by the twisted part, namely, the widths of a plurality of wires.
As a result, there the danger of cutting of the wires because the wires are strained when the wires are inserted into the gaps in each blade of the coil insertion jig 7. There is another danger that the number of regular windings of the wire will be deteriorated, which cause a decline of wire slotfil factor.
The invention has been made to solve the above problems and it is an object of the invention to prevent wire from being twisted at the time of winding with a simple construction.